[tokenadult]

The author of the article kindly submitted here, which I found quite interesting and informative, notes that she used to write for the Center for Infectious Disease Research and Policy (CIDRAP) based at my alma mater university. Sure enough, CIDRAP has its own current write-up on ebola[1] that is a good supplement to the information in the Wired article we are discussing here.

"The possibility of an airborne-transmissible Ebola virus is one 'that virologists are loath to discuss openly but are definitely considering in private,' wrote Osterholm. In its current form, the virus spreads only through contact with bodily fluids, he noted, but with more human transmission in the past few months than probably occurred in the past 500 years, the virus is getting plenty of chances to evolve."

The current rather high rate of transmission of the disease from one patient to another is alarming, and is perhaps preventable by better public-health practices aided by significant overseas funding, but if the virus haphazardly mutates into a form that spreads though more modes of transmission while still being as lethal, the world is in for a very severe challenge. As it is, the predicted number of cases by the end of the year will overwhelm several countries in the region where ebola is now spreading.

[1] http://www.cidrap.umn.edu/news-perspective/2014/09/experts-r...

[rdtsc]

How hard is it to predict (if possible at all) the mutation based on the virus type and particular strain (maybe somehow computationally simulate or mutate it) ?

In general do mutations follow probability distributions that are known?

And then let's say someone wanted to cause mutations that would make it airborne. Could they do it?

[tstactplsignore]

>In general do mutations follow probability distributions that are known?

In some ways, yes. Substitution matrices[0] describe how likely it is for an amino acid to mutate into another amino acid. However, they are generalized descriptors. At the same time, PWMs[1] describe how the probability of any given variant (mutation) is in a specific sequence, and are created by analyzing all known homologs (similar sequences) of that sequence.

However, the number of mutations required for a virus which is incapable of becoming airborne is probably large and definitely unknown. I'm not an expert in virology, but I believe that there are two requirements for a pathogen to become airborne:

A. It must infect and replicate in an area of the body capable of generating aerosols (generally, the respiratory system, like Influenza and Tuberculosis).

B. It must be good at surviving in aerosols- I believe this requires specific environmental adaptations and the right surface proteins and sugars.

I believe that Ebola meets neither requirement (especially the first), and you could see how meeting both would require not just large physical adaptation, but also a complete change in the virus' life cycle in the host.

>And then let's say someone wanted to cause mutations that would make it airborne. Could they do it?

I think in general it would be easier to start with an airborne virus, and make it deadlier. I'm not an expert but this BBC article[2] quotes that a deadly virus has never been observed to change their vector of infection.

0. http://en.wikipedia.org/wiki/Substitution_matrix

1. http://en.wikipedia.org/wiki/Position_weight_matrix

2. http://www.bbc.com/news/blogs-echochambers-29168905

[rdtsc]

That made sense. Thank you for explaining.

[alexbecker]

I have to imagine that the answer to all those questions is "no". There are simply too many variables at play, and poorly understood ones at that.